Initiator proteins are key components of the DNA replication machinery that determine where initiation will occur. in the past few years, due to a greatly improved understanding of what viral initiators look like and how they function, we can now identify the basic tasks that are required of initiators, as well as begin to comprehend what activities are required to perform these tasks. The unproved knowledge of the viral initiators also demonstrates an unexpected level of conservation between different viral initiators, which fright extend also to their cellular counterparts.